Study type: Medical/biological study (experimental study)

Short term exposure to 1439 MHz pulsed TDMA field does not alter melatonin synthesis in rats med./bio.

By: Hata K, Yamaguchi H, Tsurita G, Watanabe S, Wake K, Taki M, Ueno S, Nagawa H
Published in: Bioelectromagnetics 2005; 26 (1): 49-53
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Aim of study (acc. to author)

To clarify the effects on melatonin synthesis in rats after short-term exposure to a 1439 MHz TDMA (time division multiple access) electromagnetic field.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,439 MHz
Modulation type: pulsed
Exposure duration: continuous for 4 h
  • SAR: 7.5 W/kg average over mass (brain)
  • SAR: 2 W/kg average over mass (whole body) (for the female (283 g))
  • SAR: 1.9 W/kg average over mass (whole body) (for the male (370 g))

Exposure 1

Main characteristics
Frequency 1,439 MHz
Type
Exposure duration continuous for 4 h
Modulation
Modulation type pulsed
Pulse width 6.7 ms
Duty cycle 33.3 %
Repetition frequency 50 Hz
Additional info

TDMA signal for a PDC (Personal Digital Cellular) system
Exposure setup
Exposure source
Setup The carousel type exposure system (already used in the reference article) consisted of a small anechoic chamber, a round table with eight tubes, where rats were kept, and a quarter-wavelength monopole antenna on the metal floor.
Additional info The rats were divided into four groups: exposure, sham, cage control, and light control (LC) group. Rats in the sham group were placed in the exposure system without TDMA exposure. Those in the cage control group were not placed in the exposure system. Those in the LC group (positive control) were exposed on the last day to the light condition (400 lux) until measurement.
Parameters
Measurand Value Type Method Mass Remarks
SAR 7.5 W/kg average over mass measured and calculated brain -
SAR 2 W/kg average over mass measured and calculated whole body for the female (283 g)
SAR 1.9 W/kg average over mass measured and calculated whole body for the male (370 g)
Measurement and calculation details

SAR values were calculated by the FDTD method with numerical rat models and validated by measuring the temperature increase in the rat phantom.

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

No significant differences in melatonin and serotonin levels were revealed between the exposure, sham, and cage control groups. These data suggest that short-term exposure to a 1439 MHz TDMA electromagnetic field, which is about four times stronger than that emitted by mobile phones, does not alter melatonin and serotonin synthesis in rats.

Study character:

Study funded by

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